Protective and supporting means for apparatus for continuously coating steel strip

ABSTRACT

In order to operate a continuous steel forming and coating line at high speeds, supports for the moving steel are provided at various points such as at a location where it has its surface prepared to receive the coating and at the coating station. In addition, means are provided to shut down the line in the event there is a jam or binding causing the steel to buckle or bend creating a hazard.

O Umted States Patent [151 3,673,980 Krengel et al. 1 July 4, 1972 [54]PROTECTIVE AND SUPPORTING [56] References Cited MEANS FOR APPARATUS FOR-UNITED STATES PATENTS CONTINUOUSLY COATING STEEL STRIP 2,890,134 6/1969Linden et a1..... ..1 17/51 3,122,114 5/1965 Krengel et a1 ..29/200 [72]Inventors: Theodore ll. Krengel, 637 Park Drive, 3,559,280 2/1971Mailhiot et al. ..29/200 B Flossmoor, 111. 60422; Richard L. Pool, 3101W. 173111 SL, Hazelcrest, "I. 60429 Primary Examiner-Henry S, JaudonOct. 3 Attorney-McDougall, Hersh & Scott [21] App1.No.: 85,487 [57]ABSTRACT In order to operate a continuous steel forming and coating lineat high speeds, supports for the moving steel are provided at variouspoints such as at a location where it has its surface U.S. e ared toreceive the oating and at the coating station, In [51] -l t Cl 805 3633addition, means are provided to shut down the line in the n c 1 58 Fieldof Search ..29/200 R, 200 B, 460, 430; event there a Jam or b'ndmgcausmg the Steel to buck e or bend creating a hazard.

PATENTEnJuU-4 I972 SHEET 10F 3 INVENTORS W P'ATENTEDJULA IQR I 3,873.980

.' I snmanra PATENTEDJUL 41272 3.673.980

sum 30F 3 FIG: 4' /2( 1/40 122 118 jf w 15 II/ II III III/I IIIIIIIIIIIII IIII I 111/ 1 1/1/1111 PROTECTIVE AND SUPPORTING MEANS FOR APPARATUSFOR CONTINUOUSLY COATING STEEL STRIP BACKGROUND OF THE INVENTION Thisinvention relates generally to metal working apparatus. It relates morespecifically to apparatus useful in the high speed production of steel.

The patent to Krengel et al., US. Pat. No. 3,122,l 14, shows acontinuous tube forming and galvanizing system wherein strip materialsupplied from a reel is formed into tubing, the seam welded, and aftersurface preparation passed through a zinc bath to galvanize it. In orderto derive all possible economic benefits from such a system, it isdesired to operate it at the highest possible rates. However, as theoperating speeds of such systems are increased, it is possible onoccasion for'the formed tubing to bind at a particular station causingthe tubing to buckle or bend. Such buckling or bending, if great enough,can result in a jam or pile of bent tubing at a particular point. Apartfrom waste and losses due to the necessity to shut down the line andclear up the situation there are obvious hazards to operators andpossibilities of damage to the equipment.

In addition to the possibilities of jams, there is also a problemcreated by the movement of the formed tubing away from the center lineof its travel through the line. That is, as the tubing moves at the highspeeds desired there is a tendency to vibrate. Under certaincircumstances, these movements can build up causing binding at aparticular location or it will move toward an element such as anelectrostatic paint sprayer creating a potential fire hazard.

Therefore, it is an object of this invention to provide a novel meansfor limiting the movement of steel strip in a line which continuouslycoats such strip material and which may also form the same into desiredconfigurations.

It is another object of this invention to provide a novel means forprotection against jams and hazards in a line which continuously coatsstrip material and which may also form the same into desiredconfigurations.

It is still another object of this invention to provide a means forshutting down a line which continuously coats strip material and whichmay also form the same into desired configurations in the event apotentially hazardous situation occurs.

SUMMARY OF THE INVENTION The above and other objects are achieved in oneembodiment of the invention by providing means at various locations forrestraining movement of steel material in a line which continuouslycoats such material and forms the same into desired shapes, if desired.In order to provide for further protection against excessive stoppageand hazards, means responsive to excessive excursions of the movingmaterial are provided to stop the line.

BRIEF DESCRIPTION OF THE DRAWINGS The invention itself is set forth inthe claims appended hereto and forming a part of this application. Anunderstanding of a particular embodiment thereof may be had by referenceto the detailed description taken in conjunction with the drawings inwhich:

FIG. 1 is a block diagram illustration of a continuous tube forming andgalvanizing line which may be constructed in accordance with theinvention;

FIG. 2 is a side view, partially in section, of an acid cleaning tankforming a part of the Surface Preparation stage of the line of FIG. 1;

FIG. 3 is a plan view, partially in section, of the acid cleaning tankof FIG. 2;

FIG. 4 is a view along the lines 4-4 of FIG. 2;

FIG. 5 is a view along the lines 5-5 of FIG. 2;

FIG. 6 is a view along the lines 6-6 of FIG. 2;

FIG. 7 is a sectional elevational view of apparatus in the galvanizingstage of a continuous line in accordance with the invention;

FIG. 8 is a side view of the upper kettle forming a part of thegalvanizing stage of the line of FIG. 1;

FIG. 9 is a plan view of the upper kettle of FIG. 8;

FIG. 10 is a view along the lines 10-10 of FIG. 8;

FIG. 11 is a view along the lines 11-11 ofFlG. 10;

FIG. 12 is a view along the lines 12-12 of FIG. 10;

FIG. 13 is a view along the lines 13-13 of FIG. 8;

FIG. 14 is a partial side view of a cooling tank forming a part of thecooling stage of the line of FIG. 1;

FIG. 15 is a view along the lines 15-15 of FIG. 14;

FIG. 16 is a side view of a guide roll support mounted in the coolingtank of FIG. 14; and

FIG. 17 is an illustration of a paint booth forming a part of thepainting stage of the line of FIG. 1.

DETAILED DESCRIPTION An embodiment of this invention is shown in FIG. 1which illustrates in block diagram fonn a continuous line forgalvanizing and forming strip steel. A more detailed showing anddescription of a continuous line which may include the apparatus of theinvention is shown in the patent to Krengel et al., US. Pat. No.3,122,114. It should be understood that this showing and the referenceto the Krengel et al patent is by way of exemplification only. Forinstance, the Krengel et al patent discloses a continuous line wherestrip steel is fed from a roll of such material and formed and welded soas to produce tubing which is then galvanized in a zinc bath. However,it is contemplated that the apparatus of this invention may be used in acontinuous galvanizing line wherein the strip steel is not necessarilyformed into tubing or conduit but rather may be formed into other shapesor not formed at all. Further, that whereas reference is made togalvanizing it should be understood that the protective coating appliedto the strip material formed or unformed may be constituted by materialsother than zinc. For instance, a composition containing zinc andaluminum could be used equally well so that the phrase galvanizingmaterial" is intended to cover zinc alone or zinc in combination withother metallic materials, such as aluminum.

Referring now to FIG. 1 of the drawing, apparatus in accordance with theinvention includes a payout reel 2 on which is mounted a coil of stripsteel. The payout reel is capable of free rotational movement to pay outthe strip as required by the continuous line. In a line of this type,the strip steel is processed substantially continuously at a relativelyconstant rate therethrough. Advancement is efiected primarily byengagement between the strip steel and the forming and sizing rollsrotated at a relatively constant speed whereby the strip steel is drawninto the line for processing.

Since the lengths of the steel strip in the coils come to an end after ashort period of operation of the line and since strip is taken upcontinuously by the line in its continuous operation, it is essential toprovide means for splicing the end of one coil with the leading end ofanother coil for joinder of the strips into continuous lengths withoutstoppage of the mill in its continuous operation. This is accomplishedby providing a joining stage 4 which is constituted by a welder andappropriate clamping means. As described in U.S. Pat. No. 3,122,1l4,looping means may also be provided so as to permit the continuousoperation of the line. After joining, the strip may enter a formingstage 6 constituted by a series of conventional forming rolls wherebythe strip is deformed from a flat section to a rounded tube with theedges of the strip in abutting relation to form the seam of the tube. Aspointed out above, the forming rolls need not be tube forming rolls butmay form the strip into other desired shapes.

From the forming stage the formed strip is advanced directly to awelding stage 8 if tubing or some other closed shape is to be formed. Atthis stage the abutting free edges of the strip formed to a tubularshape are joined by welding, preferably using a continuous resistancewelder in order to keep the upset on the inside of the formed tubing ata After the tubing has been welded to provide a continuous weldthroughout the length thereof, the tubing is advanced from the weldersto elements linearly aligned therewith for washing and pickling theouter surface of the formed tubing in preparation for continuousgalvanizing. The elements for effecting this operation are designated inFIG. 1 as the surface preparation stage 10. As set out in US. Pat. No.3,122,114, the surface preparation stage includes a number of elementssuch as alkali wash for removing grease and the like from the surface ofthe steel strip or tubing, means for rinsing the wash and means forpickling the surface of the strip. This latter means in accordance withthe invention takes the form of an acid bath held in a tank 12, shown inFIG. 2, through which the moving steel passes. After pickling, the steelis once again rinsed in the surface preparation stage and then passes toa preheating stage 14. In the preheating stage, the tubing is heated toan elevated temperature, preferably a temperature above the meltingpoint of the galvanizing material so that the galvanizing reactions willbe carried out more rapidly and with greater uniformity.

After preheating, the steel passes to a galvanizing stage 16 whichincludes a housing 18 as shown in FIG. 7. In the galvanizing stage, theouter surface of the steel, if it is in the form of tubing or some otherclosed shape, is coated with the galvanizing material; otherwise thetop, bottom and side surfaces of a strip are coated. After galvanizing,the steel enters a cooling tank 21 as shown in FIG. 14. After cooling,the steel may then pass through sizing rolls which have for theirpurpose the reduction of the now galvanized material to a final desiredsize. Whereas the sizing stage 22 is shown in the embodiment of FIG. 1as being located after the cooling stage 20, if desired, this stage maybe elsewhere in the line. For instance, this stage could be locatedafter the welding stage 8 if it were desired to size the end productprior to galvanizing.

In some cases, it may be desired to coat or paint the galvanized surfacewith a pigmented material either to color it or provide additionalprotection and a painting stage 24 may be provided for that purpose.Included in the painting stage 24 is a booth 26 opened on one sidewhereby coating materials may be sprayed on the now galvanized steel asit passes through the line.

After painting in the stage 24, if such a stage is included in the line,a shear 28 is provided to cut the finished product to desired lengths.

The acid bath used in the surface preparation stage is held in the tank12 illustrated in FIGS. 2 through 6. The tank is formed so that the tankmaterial in contact with the acid is an acid resistant material such aspolypropylene. As shown in FIGS. 2 and 3, the tank 12 is an elongatedtank having a bottom 30, end walls 32 and 34, and side walls 36 and 38.Spaced from the end walls 32 and 34 are barriers 40 and 42,respectively, which with their associated end walls form compartments 44and 46, respectively. Each end wall and barrier is formed with anopening spaced upwardly from the bottom 30 aligned with each other andpositioned in line with the path of the moving steel so as to provideentry and exit openings. Spaced along the length of the tank are aplurality of supports 48, each of which is provided with an opening 50inline with the openings of the end walls and barriers. Each support 48 isprovided with an aperture 52 at its bottom so that the acid bath maypass freely between the supports and exit therefrom.

Fresh acid is supplied to the tank through a conduit 54 opening into theside of the tank and the old acid in the bath is drained through anopening 56 in the bottom 30.

The acid tank is provided with a pair of longitudinally arranged spacedapart spray pipes 55 connected to the conduit 54 and supported by thesupports 48 to overlie the formed tubing. The pipes are provided with aplurality of spray nozzles 57 positioned to direct the spray 59 on thetubing. Thus, the spray is directed forcefully from the spray nozzlesonto the tubing to react with the oxides on its surface particularlythose that are formed at the weld.

An upwardly opening channel member 60 is provided around the peripheryof the tank to receive the downwardly depending flanges 62 of a cover 64provided to prevent acid from splashing out of the tank during theoperation of the line. Handles 66 may be provided to remove the coverwhen desired.

Steel strip formed or unformed entering the acid bath holding tank 12 atthe end 32 passes through the opening in that end and that in thebarrier 40 and each of the openings 50 exiting through the openings inthe banier 42 and end 34. Inasmuch as each of the openings in thesupports and ends of this tank completely encompass the path of strip,their peripheries function to limit any excessive movement of the steelmaterial away from its desired path so as to maintain its travel insubstantially a straight line. In this manner, any tendency of the steelto oscillate along its path of travel is substantially eliminated.Consequently, the line can be operated at relatively high speeds and thesteel will not move out of its path of travel to possibly buckle andrequire that the line be shut down.

Another location in the line where it is desirable to provide guide orrestraining means is in the galvanizing stage 16. FIGS. 7 through 13illustrate the housing 18 and the guide elements provided therein tolimit the movement of the traveling steel material. FIG. 7 illustratesthe housing 18 constructed so as to provide an enclosure holding amolten reservoir of galvanizing material in an enclosed atmosphere whichis preferably constituted by a reducing or non-oxidizing gas such asnitrogen. While the housing 18 is disclosed as a sealed enclosure it isdesirable to provide a means whereby access may be had to its interiorin order to replenish the supply of galvanizing material but at the sametime maintain the inert gas atmosphere.

Thus, the housing comprises a rectangular hood 68 having a horizontallydisposed top wall 70 and side and end walls 72 which depend downwardlyfrom the edges of the tube wall into a trough 74 facing upwardly from aframe 76 which extends all about the galvanizing zone. The bottom edges78 of the side walls are received within the trough for support of thehood on the bottom wall thereof. The trough is at least partially filledwith a granular material 80 such as fine sand into which the lower edgeof the side walls become embedded to effect a sealing relationship allaround which militates against the flow of free gases for atmosphericcontrol. One or more inlets 82 for the inert or reducing gas areprovided in the walls of the hood for introduction of such gases inamounts to maintain the desired atmosphere therein.

The galvanizing means comprises an elongated horizontally disposedtrough or upper kettle 82 aligned axially with the line of travel of thesteel material for passage of the material axially through anintermediate section of the kettle forming an inlet 84 at one end to theoutlet 86 at the opposite end. Included are one or more passages 88connected to a reservoir 90 of molten galvanizing material with meansfor displacement of the molten material from the reservoir to the inletsat a rate sufficient to maintain the kettle substantially filled withmolten galvanizing material so as to cover the steel advancingtherethrough.

As seen in FIGS. 8 and 9, the upper kettle includes a first side wall 91and a second side wall 92 and that the side wall 91 is higher than theside wall 92. Mounted on the side wall 91 are a plurality of brackets 94which are substantially T-shape in cross section. Each bracket isprovided with vertically extending slots 96 through which suitablefastening means such as bolts 98 may be passed to engage in appropriatethreaded holes in the side wall 91 so that the brackets may be adjustedin a vertical direction. The leg of each T-shaped bracket is providedwith an opening in which is mounted a guide 100, the inner periphery ofwhich is shaped to conform substantially to the surface of the steelmaterial being galvanized. As may be seen, the openings formed by theinner peripheries 102 of the guides 100 are aligned with each other andwith the path of travel of the moving steel material so that theyfunction to maintain the path of travel in substantially a straightline. The

material selected for the guides 100 should be one which will resistalloying with the galvanizing material so as to prevent a build up ofsuch material on the guide whereby it will maintain its desired size andconfiguration. The guides thus provide a means to restrain any tendencyof rapidly moving material to oscillate about its path of travel andtherefore are part of the means to permit operation of the line atrelatively high speeds.

In order to provide for a continuous flow of molten galvanizing materialin the upper kettle 82 and at the same time maintain the level ofmaterial in that kettle high enough to completely cover thesteelmaterial moving therethrough, one end of the side wall 92 is cut away soas to provide a lower level portion 104. A trough 106 extends from theportion 104 so that molten material entering the upper kettle throughthe passage 88 drains through the portion 104 down the trough 106 backto the reservoir 90.

The tank 21 forming a part of the cooling stage 20 is illustrated inFIGS. 14 through 16. The tank is maintained with a continuouslycirculating bath of cooling water so that the hot galvanized material iscooled as it passes therethrough causing the galvanizing material tosolidify on the surface of the steel. Mounted in the cooling tank 21 area pair of guide roller supports 108. Each guide roller support isconstituted by a pair of angular brackets 110 and 112 secured to thebase of the tank 22. Mounted on vertically extending portions 114 and116, respectively, of the brackets 110 and 112 are a pair of slidemembers 118 and 120 connected by a cross piece 122 so as to form aU-shape configuration. Each slide member is provided with elongatedvertically extending slots 124 through which pass threaded fasteningmeans 126 engaging in the bracket portions 114 and 116 so that thevertical height of the slide members can be adjusted. Mounted onsuitable bearing means on a shaft 128 extending between the bracketportions 114 and 116 and mounted on the shaft is a guide roller 130 onwhich the moving steel material is supported.

Secured by means of threaded fasteners 132 extending through verticalslots 134 is a third slide element 136. Mounted on top of the thirdslide element 136 is a limit switch 138 having an actuator 140 extendingover the path of travel of the strip material. By adjusting the verticalheight of the slide element 136 a limit can be fixed for any verticalmovement of the strip material, this limit being determined by theheight of the switch actuator 140. If the moving strip material shouldbe caused for one reason or another, such as a jam or binding some placein the line, to move upwardly out of its path of travel, it will contactthe switch actuator 140 causing the switchl30 to be operated. The switch130 is connected by leads 141 into the electrical power and controlcircuit of the line in a manner not shown so as to be effective tointerrupt the electric power to the various drive motors in the line soas to shut them down in the event of excess movement of the steelmaterial.

When the line is provided with a coating stage as indicated at 24 inFIG. 1, a spray booth such as shown at 26 in FIG. 17 may be provided.The booth is closed on all sides except one, 142, so that desiredcoating such as paint may be sprayed upon the now galvanized steelmaterial. One side of the booth 26 is provided with an entry opening 144while its other side is provided with an exit opening 146. Mounted onthe wall of the booth around the exit opening 146 is a support 148 onwhich is mounted four limit switches 150, each having an actuator 152.The actuators are positioned a predetermined distance away from the pathof travel of the steel material so as to lie in planes over and underand to either side of the path of travel. In the event that the materialshould depart more than a predetermined distance from its desired pathof travel, one or more of the actuators will be contacted to operate itsassociated limit switch. The associated limit switches, as before, maybe connected into the electrical system for the line in order to shut itdown in this eventuality.

In addition, since the spraying apparatus may be constituted by anelectrostatic spray system, the switches may be connected to the powersupply for that system to interrupt it in the event of excess movementof the steel material. This is particularly important since theelectrical potential in the vicinity of such spraying apparatus is veryhigh and very frequently the coatings or paint used are inflammable sothat if the steel material were to move to the vicinity of the sprayingapparatus inasmuch as it is an electrical conductor a spark may becreated igniting the coating material.

Each of the guide or restraining elements and the protective limitswitches provided at the locations indicated cooperate to permit theline to operate at relatively high speeds by restraining the rapidlymoving steel material in a desired path and act to stop the operation ofthe line in the event that the steel material moves from the desiredpath an excessive amount in certain strategic locations.

Obviously, various elements of the invention may be modified and it isintended to cover by the claims appended hereto all such modificationsas fall within their scope.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. Apparatus for the continuous galvanizing of steel supplied to theapparatus in the form of rolled strip comprising means for preparing thesurface of the steel for galvanizing including an elongated tank forholding an acid bath, said tank formed from an acid resistant material,a plurality of spaced supports mounted in said tank along the lengththereof, each support having an opening in line with the othersupporting openings and in line with the moving steel, a galvanizingstage including a kettle for holding molten galvanizing material, saidkettle having a bottom and side and end walls upstanding therefrom, anopening in each end wall in line with each other and the moving steelwhereby the steel may enter at one end of the kettle and exit from theother, a plurality of guides mounted for vertical adjustment on one sidewall of said kettle for holding the moving steel in a relatively fixedpath as it passes through said kettle, a cooling stage including acooling tank following said galvanizing stage, and at least one guideroller support having a vertically adjustable roller thereon mounted insaid cooling tank.

2. The apparatus of claim 1 wherein each spaced support in saidelongated acid bath holding tank is provided with an aperture at itsbottom.

3. The apparatus of claim 2 wherein said elongated acid bath holdingtank is provided with barriers spaced from each end wall thereof formingcompartments and said barriers are provided with openings in line withsaid support openings to permit passage of the moving steel.

4. The apparatus of claim 3 wherein said barriers are provided withapertures at the bottom to permit liquid flowing through said barrieropenings into said compartments to flow back into said tank.

5. The apparatus of claim 4 wherein said elongated acid bath holdingtank is provided with an upwardly facing channel extending around itsperiphery and a cover including downwardly depending flangers engageablein said channel.

6. The apparatus of claim 1 wherein said kettle is mounted in a housingfor holding a bath of molten galvanizing material and is spaced abovethe level of the bath, and said guides are mounted in brackets eachhaving a base and a flange extending nonnally to said base.

7. The apparatus of claim 6 wherein the base of each bracket is providedwith slots, attaching means passing through said slots and one side wallof said kettle to vertically and adjustably mount each bracket and guideon said one side wall.

8. The apparatus of claim 7 wherein said one side wall is higher thanthe other side wall of said kettle and the base of each bracket extendson said one side wall above said other side wall.

9. The apparatus of claim 7 wherein a portion of one of the side wallsof said kettle is lower than the rest of that side wall and a troughextends downwardly from said lower portion toward the bottom of saidhousing to permit galvanizing material held in said kettle to return toa bath of molten galvanizing material held in said housing.

10. The apparatus of claim 1 wherein a vertically adjustable limitswitch is mounted above said guide roller and has an actuating elementextending over said guide roller above the path of the moving steelwhereby said switch may be actuated in the event the moving steel movesout of its desired path in excess of a predetermined amount.

1 1. The apparatus of claim 10 wherein said guide roller supportcomprises a pair of angular supports and said guide roller is mountedbetween said supports.

12. The apparatus of claim 1 1 including a pair of slide members havingslots therein each engaging one of said angular supports, securing meanspassing through said slots to permit said slide members to be verticallyadjustably secured to said angular supports, and bearing means mountingsaid guide roller on said slide members.

13. The apparatus of claim 12 including a third slide member havingslots therein adjustably mounted on one of said angular supports andsaid limit switch is mounted on said third slide member.

14. The apparatus of claim 1 including a stage for coating thegalvanized steel with a pigmented protective coat including a spraybooth having entry and exit openings in line with the path of the movingsteel and limit switch means having actuating means extending around thepath of the moving steel around one of said openings to be actuated ifthe moving steel moves out of a predetermined path.

15. The apparatus of claim 14 wherein said limit switch means includesfour limit switches each having a separate actuator and the actuatorsare disposed over, under and on either side of the path of moving steel.

1. Apparatus for the continuous galvanizing of steel supplied to theapparatus in the form of rolled strip comprising means for preparing thesurface of the steel for galvanizing including an elongated tank forholding an acid bath, said tank formed from an acid resistant material,a plurality of spaced supports mounted in said tank along the lengththereof, each support having an opening in line with the othersupporting openings and in line with the moving steel, a galvanizingstage including a kettle for holding molten galvanizing material, saidkettle having a bottom and side and end walls upstanding therefrom, anopening in each end wall in line with each other and the moving steelwhereby the steel may enter at one end of the kettle and exit from theother, a plurality of guides mounted for vertical adjustment on one sidewall of said kettle for holding the moving steel in a relatively fixedpath as it passes through said kettle, a cooling stage including acooling tank following said galvaNizing stage, and at least one guideroller support having a vertically adjustable roller thereon mounted insaid cooling tank.
 2. The apparatus of claim 1 wherein each spacedsupport in said elongated acid bath holding tank is provided with anaperture at its bottom.
 3. The apparatus of claim 2 wherein saidelongated acid bath holding tank is provided with barriers spaced fromeach end wall thereof forming compartments and said barriers areprovided with openings in line with said support openings to permitpassage of the moving steel.
 4. The apparatus of claim 3 wherein saidbarriers are provided with apertures at the bottom to permit liquidflowing through said barrier openings into said compartments to flowback into said tank.
 5. The apparatus of claim 4 wherein said elongatedacid bath holding tank is provided with an upwardly facing channelextending around its periphery and a cover including downwardlydepending flangers engageable in said channel.
 6. The apparatus of claim1 wherein said kettle is mounted in a housing for holding a bath ofmolten galvanizing material and is spaced above the level of the bath,and said guides are mounted in brackets each having a base and a flangeextending normally to said base.
 7. The apparatus of claim 6 wherein thebase of each bracket is provided with slots, attaching means passingthrough said slots and one side wall of said kettle to vertically andadjustably mount each bracket and guide on said one side wall.
 8. Theapparatus of claim 7 wherein said one side wall is higher than the otherside wall of said kettle and the base of each bracket extends on saidone side wall above said other side wall.
 9. The apparatus of claim 7wherein a portion of one of the side walls of said kettle is lower thanthe rest of that side wall and a trough extends downwardly from saidlower portion toward the bottom of said housing to permit galvanizingmaterial held in said kettle to return to a bath of molten galvanizingmaterial held in said housing.
 10. The apparatus of claim 1 wherein avertically adjustable limit switch is mounted above said guide rollerand has an actuating element extending over said guide roller above thepath of the moving steel whereby said switch may be actuated in theevent the moving steel moves out of its desired path in excess of apredetermined amount.
 11. The apparatus of claim 10 wherein said guideroller support comprises a pair of angular supports and said guideroller is mounted between said supports.
 12. The apparatus of claim 11including a pair of slide members having slots therein each engaging oneof said angular supports, securing means passing through said slots topermit said slide members to be vertically adjustably secured to saidangular supports, and bearing means mounting said guide roller on saidslide members.
 13. The apparatus of claim 12 including a third slidemember having slots therein adjustably mounted on one of said angularsupports and said limit switch is mounted on said third slide member.14. The apparatus of claim 1 including a stage for coating thegalvanized steel with a pigmented protective coat including a spraybooth having entry and exit openings in line with the path of the movingsteel and limit switch means having actuating means extending around thepath of the moving steel around one of said openings to be actuated ifthe moving steel moves out of a predetermined path.
 15. The apparatus ofclaim 14 wherein said limit switch means includes four limit switcheseach having a separate actuator and the actuators are disposed over,under and on either side of the path of moving steel.